EP3524778B1 - Lever connection of a guide vane adjustment for turbomachines and associated method of manufacturing - Google Patents

Description

The invention relates to a lever connection of a guide vane adjustment of a turbomachine for producing a connection between a guide vane and an actuator according to the preamble of claim 1, a method for producing a connection between a guide vane and an actuator and a turbomachine.

Compressors in axial flow machines, for example aircraft engines, generally include a guide vane adjustment in the area of the front compressor stages or in the high-pressure compressor. As a result of the guide vane adjustment, the guide vanes of the relevant guide vane row are adjusted around their vertical axis as a function of the speed, so that an absolute stator outflow angle can be changed. This can prevent a stall when starting up the turbo machine or at low speeds. A step load is reduced. Alternatively, a stall could also be achieved by adjusting the rotor blades of the compressor stages, but this is technically much more complicated, so that the adjustment of the guide blades has prevailed.

The adjustment of the guide vanes of a guide vane row is conventionally carried out mechanically by actuating an actuator. The actuator acts on the guide vanes via an adjusting ring and an adjusting lever. The adjusting ring is arranged outside the turbomachine and is usually positioned behind and coaxially of the row of guide vanes, viewed in the direction of flow. It is displaceable in the circumferential direction and in the axial direction of the turbomachine. If there are several compressor stages to be adjusted, the adjusting rings are simultaneously controlled via an adjusting lever of the actuator which is rotatably mounted on the compressor housing and which extends in the axial direction of the turbomachine and is connected to the adjusting rings.

In known guide vane adjustments, the adjusting lever, also referred to below for the sake of simplicity, is slipped in the radial direction of the turbomachine onto a vane shaft extending in the vertical direction of the guide vane. Then the lever is positively fixed to a contact area of the blade shaft and screwed secured in position. The screw connection can take place through an internal thread or through an external thread. This type of lever connection requires a sufficiently thick blade shaft for the design of the contact surfaces. However, due to the geometric boundary conditions such as small flow channel diameter and high number of blades, the shaft diameter can hardly be larger than the smallest possible external thread. If the shank diameter now has to be reduced significantly due to the geometric boundary conditions, the known lever connection described above can no longer be represented with shank diameters that are hardly larger than the permissible thread size. For engine compressors, therefore, a challenge lies in the significant reduction in the size of the geometry, ie a miniaturization of the adjusting blades as well as their connection with an adjusting lever. Conventional connection systems using roof slopes, cone geometries and the like require a reduction in the diameter of the blade shaft in the outer area, which no longer allows the use of screws or nuts with a minimum thread diameter of M5.

Prior art is in the patent EP 1 561 906 B1 shown. In the lever connection shown here, the adjusting lever has a claw-like connection section for connection to a blade shaft. The connecting section has two opposing claw elements which extend from an underside of the adjusting lever and delimit a slot extending in the longitudinal direction of the lever. The slot is open on both of its front sides over its entire cross section. An elongated hole is made in its slot base that represents an opening to the top of the adjusting lever. For assembly, the lever with its slot is pushed over the blade shaft until its opposing claw surfaces are in a non-rotatable form fit with corresponding shaft surfaces. Subsequently, the lever is secured radially to the vane shaft by means of a screw element screwed into an internally threaded bore of a free end of the vane shaft, which screw element is guided through the elongated hole. The document US 2008/107520 A1 discloses the connection of an adjustable guide vane to an adjustment ring, the vane shaft having a tapered area with parallel contact surfaces and the lever at its end having an axial recess in which the tapered region of the vane shaft is positively received.

A lever connection with a slot in a connecting section of an adjusting lever is also in the patent EP 2 273 074 B1 shown. In this solution, the slot is delimited by lateral hook elements which, in the assembled state, engage in lateral grooves in a shovel shaft. The slot is opened via a bore to the top of the adjusting lever for passing through a screw element.

The object of the invention is to provide a lever connection of a guide vane adjustment of a turbomachine for producing a connection between a guide vane and an actuator which eliminates the disadvantages mentioned. In addition, it is the object of the invention to create a method for producing a connection between a guide vane and an actuator and to provide a fluid flow machine which enables a large number of adjustable guide vanes with a small installation space.

The object is achieved by a lever connection with the features of patent claim 1, by a method with the features of patent claim 7 and by a flow machine with the features of patent claim 9.

A lever connection according to the invention of a guide vane adjustment of a turbomachine for establishing a connection between a guide vane and an actuator, wherein the guide vane has a vane shaft which extends along its vertical axis and which can be brought into connection by means of a lever with an adjusting ring of the actuator, provides that the blade shaft has a contact area which is reduced in cross-section compared to a radially outer shaft area. The lever has a connecting section with an elongated hole and a threading opening. The elongated hole has opposite key surfaces for a rotationally fixed operative connection with contact surfaces of the contact area. The threading opening merges into the elongated hole on the circumferential side and has a wider cross-section than the elongated hole. It is enlarged in cross-section in such a way that the lever can be pushed radially onto the blade shaft with its connecting section via the threading opening.

The combination of elongated hole with threading opening creates a keyhole-shaped recess in plan view, which enables the blade shaft diameter in the area radially outside of the shaft-lever connection point to have the same diameter as radially inside. The height of the contact surfaces for transmitting the torque of the adjustment forces via the lever does not affect the outer diameter of the blade shaft, as is the case with conventional connections such as wedge surfaces or cone geometries. This means that a minimum diameter of 5 mm, driven by an M5 lock nut for the blade shaft, can be achieved. The part of the blade shaft located radially on the outside can have exactly the same diameter as the part of the blade shaft located radially on the inside. A further advantage is that the lever does not lift off after it has reached its desired position on the shovel shaft can be, but quasi automatically enters into a self-locking non-rotatable locking with the shovel shaft when its target position is reached. The transmission of the torque from the actuator for adjusting the blades is thus carried out via the form fit.

In other words, because of the threading opening, the diameter of the contact area does not have to be larger than the outer diameter of the radially outer shaft area, so that the lever connection according to the invention is also suitable for very small shaft diameters. The blade shaft diameter is therefore no longer the decisive variable in the formation of the contact area. A reliable connection of the lever to the blade shaft is thus possible even with a small blade shaft diameter. As a result, the lever connection is particularly suitable for use in compressors of turbomachines which require a large number of blades with a small available installation space, such as aircraft engines or compact industrial gas turbines. Due to the virtually non-existent geometric boundary conditions of the blade shaft, the shaft diameter can be reduced significantly.

In one embodiment, a form fit between the connecting section of the lever and the contact area of the blade shaft is achieved in that the key surfaces and corresponding contact surfaces are each parallel surfaces. The contact areas are preferably identical in size and shape. For assembly reasons, the key surfaces are preferably also the same size and shape. Alternatively, the key surfaces and the contact surfaces can be set at an angle to one another. For example, when viewed in the longitudinal direction of the blade shaft, the wrench surfaces and contact surfaces can be positioned in relation to one another in a manner similar to the legs of an isosceles triangle, quasi-roof-shaped. As an alternative to a roof-shaped angular position to one another, a multi-angled, trapezoidal and similar alignment and the like is also conceivable. For example, the wrench surfaces and / or the contact surfaces can be set so that insertion bevels are formed in the transition area from the threading opening into the elongated hole, which form a kind of funnel tapering in the assembly direction and facilitate the transition of the blade shaft from the threading opening into the elongated hole during assembly . It is essential that the key surfaces and the contact surfaces are not designed to be rotationally symmetrical with respect to the vertical axis, and that the form fit is free of play. In principle, a key surface and a corresponding contact surface are sufficient to achieve a rotationally fixed locking.

In terms of manufacturing technology, the contact surfaces can be worked out simply by tapering the cross-section of the blade shaft. For example, they can be produced by milling. The design as cross-sectional tapering also results in shoulder surfaces in the transition area of the contact areas to a shaft area radially inwardly adjacent to the contact area, which act as a support for the connecting section in the assembled state.

The lever can also be clamped to the blade shaft by means of a screw element. The screw element can, for example, be a nut which interacts with the radially outer shank area, in particular a free end, of the blade shank. The nut is preferably self-locking. Instead of an external thread, an internal thread can in principle also be formed with a corresponding adaptation of the nut. To secure the bracing, a securing element can additionally be provided for arrangement between the connecting section and the screw element, which, for example, has an angled arm for laterally resting on the screw element and / or the connecting section. After clamping, the at least one arm can be placed on the screw element and / or the connecting section without using additional tools. In particular, several arms can also be provided, so that reliable securing is still guaranteed if one arm fails. The transmission of the torque from the actuator for adjusting the blades is preferably carried out exclusively via the form fit. The screw element serves primarily to secure the lock.

To connect the lever to the adjusting ring, the lever can interact with an adjusting ring pin which is set up so that the lever is mounted on the adjusting ring by means of a radial movement. The lever preferably has a passage or through-hole through which the respective adjusting ring pin is guided. This allows a quick and safe assembly. In order to specify a target position of the adjusting ring in the lever-side through hole, the adjusting ring pin can have, for example, an annular shoulder that acts as a slide-on or immersion limitation. The adjusting ring pin is preferably fastened to the lever after it has reached its desired position.

In a method according to the invention for producing a connection between a guide vane and an actuating drive, the guide vane having a vane shaft that extends extends along its vertical axis and which is directly or indirectly connected to an adjusting ring of the actuator by means of a lever, the lever is pushed radially onto the vane shaft from a first assembly direction and then positively locked with the vane shaft by a movement in a second assembly direction. The second mounting direction and the second mounting direction are different. The first assembly direction and the second assembly direction preferably run orthogonally to one another, for example the second assembly direction runs in the axial direction. Due to the different type of second assembly direction, locking takes place without any tension. The lever can now neither lift nor move radially inwards or radially outwards.

• radiales Aufschieben des Hebels auf den Schaufelschaft über eine hebelseitige Einfädelöffnung und radiales Verbinden des Hebels mit dem Verstellring,
• axiales Verschieben des Verstellrings mit dem Hebel entlang eines hebelseitigen Langlochs bis sich gegenüberliegende Schlüsselflächen des Langloches in Anlage mit korrespondierenden Kontaktflächen des Schaufelschaftes befinden,
• Verspannen des Hebels mit dem Schaufelschaft durch Zusammenwirken eines Schraubelements mit einem radial äußeren Schaftbereich, wobei der Hebel zwischen schaftseitigen Schulterflächen und dem Schraubelement radial eingespannt wird.

A preferred method comprises the steps

• radial pushing of the lever onto the blade shaft via a lever-side threading opening and radial connection of the lever with the adjusting ring,
• axial displacement of the adjusting ring with the lever along an elongated hole on the lever side until opposite key surfaces of the elongated hole are in contact with the corresponding contact surfaces of the blade shaft,
• The lever is braced with the blade shaft by the interaction of a screw element with a radially outer shaft region, the lever being clamped radially between the shoulder surfaces on the shaft side and the screw element.

A turbomachine according to the invention has a large number of the lever-type connections according to the invention for establishing a connection between guide vanes of an adjustable vane row and an actuator. The lever connections according to the invention allow guide vane adjustments in guide vanes with a very small shaft diameter and / or at a very close distance from one another. For example, the guide vane adjustments of the front compressor stages or of the high-pressure compressor have such lever connections so that the turbo machine can be equipped with a very powerful or performance-optimized compressor.

Other advantageous exemplary embodiments of the invention are the subject of further dependent claims.

Figur 1:

eine perspektivische Draufsicht auf einen Abschnitt einer Leitschaufelverstellung mit erfindungsgemäßer Hebelanbindung,

Figur 2:

eine Draufsicht auf einen Hebel der Hebelanbindung,

Figur 3:

eine Seitenansicht des Hebels aus Figur 2,

Figur 4:

eine perspektivische Draufsicht auf einen Abschnitt eines Schaufelschaftes der Hebelanbindung,

Figur 5:

einen Längsschnitt durch die Leitschaufelverstellung aus Figur 1,

Figur 6:

einen Längsschnitt durch die Leitschaufelverstellung aus Figur 1 und

Figur 7 bis 9:

Montageschritte zur Montage der Hebelanbindung.

In the following, preferred exemplary embodiments of the invention are explained in more detail with the aid of greatly simplified schematic drawings. It goes without saying that individual elements and components can also be combined differently than shown. Reference symbols for elements that correspond to one another are used across the figures and may not be described anew for each figure. Show it:

Figure 1:

a perspective top view of a section of a guide vane adjustment with a lever connection according to the invention,

Figure 2:

a top view of a lever of the lever connection,

Figure 3:

a side view of the lever Figure 2 ,

Figure 4:

a perspective top view of a section of a blade shaft of the lever connection,

Figure 5:

a longitudinal section through the guide vane adjustment Figure 1 ,

Figure 6:

a longitudinal section through the guide vane adjustment Figure 1 and

Figure 7 to 9:

Assembly steps for assembling the lever connection.

In general, terms such as “radial”, “radially outside”, “radially inside”, “coaxial” and “circumferential direction” relate to a machine longitudinal axis X of the turbo machine according to the invention, which represents the axis of rotation of a rotor of the turbo machine.

Figure 1 shows a guide vane adjustment of guide vanes of an adjustable guide vane row of a turbomachine. Due to the selected view from the outside of a housing section of the turbomachine, only one blade shaft 1 leading radially outward from the blade is shown of the rotating blades. The blade shaft 1 is usually also referred to as a radially outer bearing journal. In principle, the guide vane has a blade which is located in a flow channel of the turbomachine through which the main flow flows. The guide vane is mounted in an inner ring via a bearing journal radially inner to the vane blade, which surrounds a rotor shaft at a radial distance. The turbomachine is, for example, an aircraft engine and the row of guide vanes is arranged in the compressor of the aircraft engine.

To form a lever connection 2 according to the invention for the guide vane adjustment, the guide vane has the vane shaft 1 which extends radially outward from the vane blade and which is led out of the flow channel of the turbomachine and its housing 4 and which runs along the vertical axis H of the guide vane. By means of an adjusting lever or lever 6 of the lever connection 2 that is located outside the main flow path of the turbomachine, the vane shaft 1 and thus the guide vane are in operative connection with an adjusting ring 8 arranged coaxially to the guide vane row and outside the main flow path of the turbomachine. The adjusting ring 8 is in Figure 6 outlined. The connection of the lever 6 to the adjusting ring 8 takes place via adjusting ring pins 10. The lever 6 is braced on the blade shaft 1 by means of a screw element 12, for example a self-locking nut.

To adjust the guide vanes 1 about their vertical axes H, the adjusting ring 8 is displaced along the housing 4 via an actuator (not shown). The shift then causes a corresponding pivoting of the guide vanes around their Hochachen H. The torque is transmitted from the lever 6 to the guide vane via a form fit between the lever 6 and the vane shaft 1, which will be explained below. The screw element 12 serves primarily to secure the Form fit. Each guide vane of the adjustable guide vane row is provided with such a lever connection 2, each of which is connected to the adjusting ring 8.

As in the Figures 2 and 3 outlined, the lever 6 has a connecting portion 14 for connection to one in the Figures 4 and 5 The contact area 16 shown of the blade shaft 1 and a connecting section 18 for connection to the adjusting ring pin 12. The connecting section 18 for connecting to the adjusting ring pin 12 is referred to below for the sake of clarity. The connecting section 14 and the connecting section 18 form the two ends of the lever 6 and are connected to one another via a strip-like lever section 20. The axis of rotation of the connecting section 14 about the vertical axis H and the axis of rotation of the connecting section 18 about a longitudinal axis of the adjusting ring pin 10 are parallel and preferably run in the radial direction. A possible radial offset of the connection section 14 and the connection section 18 can be compensated for by the strip-like lever section 20 in that the lever section 20 is arranged at an angle on the connection section 14 and the connection section 18, as shown in FIG Figure 2 is shown. This angle can be 90 °. However, a longitudinal extension of the lever section 20 preferably deviates from the essentially perpendicular perpendicular between the two axes of rotation. This facilitates the assembly of the lever 6.

The connecting section 14 is made thicker than the strip-like lever section 20 and has a rectangular shape extending in the longitudinal direction L of the lever 6. It has a keyhole-like recess 22 that extends it in its thickness direction (in Figure 2 perpendicular to the plane of the sheet) interspersed from its upper side to the lower side.

The recess 22 is formed by an elongated hole 24 that extends in the longitudinal direction L of the lever and has two opposing key surfaces 26, 28. The key surfaces 26, 28 are designed here as plane parallel surfaces which are spaced apart from one another over a constant distance and which run in the direction of the longitudinal axis L of the lever. They are connected to one another near the strip-like lever section 20 via a concave surface 30.

In addition, the recess 22 is formed by a threading opening 32. From the perspective of the strip-like lever section 20, the threading opening 32 lies behind the elongated hole 24 and is open on the circumference of this. In other words, the threading opening 32 merges into the elongated hole 24 at the end of the elongated hole 24 facing away from the concave surface 30. In the exemplary embodiment shown here, the threading opening 32 is designed as a through hole with a circular cross section. Compared to the elongated hole 24, the threading opening 32 is enlarged in cross-section in the width direction B of the lever 6. It has such a cross section that the blade shaft 1 with its in the Figures 4 and 5 radially outer free end 34 shown can be passed or that the lever 6 can be pushed onto the free end 34 of the blade shaft 1.

The connection section 18 is thickened compared to the strip-like lever section 20, but not as much as the connection section 14. It has a through-hole 36 for the passage of the adjustment ring pin 10 or for the radial pushing of the lever 6 onto the adjustment ring pin 10.

The strip-like lever section 20 is designed here with a constant thickness and width. To compensate for radial heights with respect to the shaft-lever connection point and the adjusting ring pin-lever connection point, a height compensation between the connection section 14 and the connection section 16 can be effected via the strip-like lever section 20 by means of a corresponding deformation

According to the Figures 4 and 5 the blade shaft-side contact area 16 has two opposite contact surfaces 38, 40 for engaging the lever-side connecting section 14. The contact surfaces 38, 40 are designed to correspond to the key surfaces 26, 28 of the elongated hole 24 and are thus planar parallel surfaces here. They are flattened peripheral sections of the blade shaft 1 and are connected to one another via unchanged convex peripheral surfaces 42 of the blade shaft 1. Due to the perspective, only a circumferential surface 42 can be seen. In particular, the contact surfaces 38, 40 are local cross-sectional tapers of the blade shaft 8, which are spaced from one another in such a way that, in the assembled state, there is a play-free or almost play-free form fit with the key surfaces 26, 28. In contrast to the radially outer free end 34 or radially outer shank area of the blade shaft 1 and a radially inner adjoining shank area 44, the contact area 16 is not rotationally symmetrical to the vertical axis H, which basically enables the lever 6 to be secured against rotation by a form fit.

In the transition region of the contact surfaces 38, 40 to the original shaft region 44 adjoining radially on the inside, shoulder surfaces 46, 48 are formed. The shoulder surfaces 46, 48 form supports for the connecting section 14 in the clamped state and limit a radial position of the lever 6 on the blade shaft 1. They enable the clamping with the screw element 12 in the first place.

The free end 34 of the blade shaft 1 is provided with an external thread, not shown, for interaction with the screw element 12 and is thus designed as a threaded section. As in Figure 7 outlined, the external thread or the free end 34 is spaced apart from the contact area 16 via an annular groove 50. In principle, instead of an external thread, it is also possible to provide an internal thread in the free end 34 for interaction with a corresponding screw element 12.

In Figure 6 the locking and bracing of the lever 6 on the blade shaft 1 in the contact area 16 is shown in section. It can be clearly seen how the blade shaft 1 is not arranged in the threading opening 32, but rather in the elongated hole 24 and in particular penetrates this. In the exemplary embodiment shown here, the concave surface 30 of the elongated hole 24 acts as an axial stop for the blade shaft 1. However, contact is not absolutely necessary. Rather, the elongated hole 24 allows the compensation of manufacturing and assembly tolerances, see above that the blade shaft 1 can in principle also be spaced apart from the concave surface 30 in its mounted position as long as it is located in the elongated hole 24.

In addition, the tensioning of the lever 6 by means of the screw element 12 can be seen. The connecting section 14 is clamped between the shoulder surfaces 46, 48 and the screw element 12 and is at a radial distance from the housing 4 of the turbomachine. In addition, as shown, a washer 52 can be placed on the blade shaft 1 between the connecting section 14 and the screw element 12. In order to enable a smooth adjustment of the guide vane about its vertical axis H, the vane shaft 1 is guided through a bearing bush 54 which is inserted into the housing 4.

Furthermore, in Figure 6 to recognize. how the lever 6 interacts with the adjusting ring pin 10. This is guided through the through hole 36 in the connection section 18 of the lever 6 and has an annular shoulder 56 for setting its immersion depth, which at the same time forms a radial support for the lever 6.

Furthermore, the radial height difference between the shaft-lever connection point and the adjusting ring pin-lever connection point can be clearly seen. In the exemplary embodiment shown here, the connection on the blade shaft side is located radially inward to the connection on the adjustment ring side.

The shaft-lever connection point is also arranged here behind the adjustment ring pin-lever connection point, viewed in the direction of flow. However, viewed in the direction of flow, the shaft-lever connection point can also be arranged in front of the adjusting ring pin-lever connection point. The axial position of the connection points with respect to one another determines, among other things, a free assembly space outside the housing 4.

In a method according to the invention for mounting the lever connection 2 according to the invention on a blade shaft 1 of a guide vane of a guide vane row, it is essential that the lever 6 of the lever connection 2 is pushed radially or essentially radially onto the contact area 16 of the vane shaft 1 in a first mounting direction ( Figure 7 ) and is positively locked with the blade shaft 1 by means of a movement in an axial or essentially axial second assembly direction ( Figure 8 ). Before the lever 6 is pushed on radially on the shaft-side contact area 16, the lever 6 on the adjusting ring 8 is off mounted in a mounting direction that is the same as the first mounting direction. The lever 6 is thus moved radially after the adjustment ring pin 10 has been installed until its connecting section 14 is in contact with the contact area 16 of the blade shaft 1. The movement in the second assembly direction does not take place until all levers 6 have been placed on the respective blade shaft 1 and threaded into the adjusting ring 8

The following is based on the Figures 7 to 9 a detailed explanation of the method according to the invention. As mentioned above, information such as "radial" relates to the machine longitudinal axis X of the turbo machine according to the invention, which represents the axis of rotation of a rotor of the turbo machine.

At the beginning of the assembly ( Figure 7 ) an adjusting ring pin 10 is attached to the respective lever 6. For this purpose, the adjusting ring pin 10 is guided through the through hole 36 of the connecting section 18 up to the ring shoulder 56 and then connected to it.

Subsequently ( Figures 7 and 8 ) the lever 6 is pushed by means of its threading opening 32 of the keyhole-like recess 22 radially onto the blade shaft 1, ie in the direction of the arrow along the vertical axis H, over its free end 34. The lever 6 now engages with its threading opening 32 around the shaft-side contact area 16 ( Figure 8 ). The adjusting ring pin 10 is accordingly introduced radially into an opening 58 of the adjusting ring 8 (see FIG Figure 6 ).

Then the positive connection is established between the lever 6 and the blade shaft 1 ( Figures 8 and 9 ). For this purpose, the adjusting ring 8, not sketched, is moved axially with the lever 6 in the direction of the blade shaft 1, ie along the machine longitudinal axis X in the direction of the arrow. shifted in such a way that the contact area 16 merges from the threading opening 32 into the elongated hole 24 of the keyhole-like recess 22. The key surfaces 26, 28 of the elongated hole 24 are now in contact with the contact surfaces 38, 40 of the contact area 16. The non-rotatable form fit between the lever 6 and the blade shaft 1 is thus established. At the same time, due to the enlarged diameter of the free end 34 of the blade shaft 1 and of the blade area 44 adjoining the contact area radially on the inside, the lever 6 is locked in the radial direction on the blade shaft 1.

After the axial displacement has taken place, the form fit is secured ( Figure 9 ). For this purpose, the lever 6 is braced against the shoulder surfaces 46, 48 of the blade shaft 1 by means of the screw element 12. The screw element 12 is screwed onto the external thread of the free end 34. Due to the radial support on the shoulder surfaces 46, 48 of the blade shaft 1, the connecting section 14 cannot deflect radially inward. As a result, the connecting portion 14 is pressed against the shoulder surfaces 46, 48. The screw element 12 is secured against loosening rotational movements by self-locking. In addition, the washer 52 can be designed as a locking washer with, for example, lateral arms which are placed laterally against the screw element 12 and / or inserted into the threading opening 32.

It is mentioned that the invention also includes embodiments in which the adjusting ring pins 10 are not preassembled with the levers 6. For example, the adjusting ring pins 10 can be mounted beforehand on the adjusting ring 8 and then the levers 6 can be pushed onto the respective adjusting ring pin 10 mounted on the adjusting ring 8.

Disclosed is a lever connection of a guide vane adjustment for connecting a guide vane of a turbomachine with an adjusting ring of an actuator, which is set up in such a way that an adjusting lever of the lever connection is pushed radially onto a blade shaft of the guide vane from a first assembly direction with respect to a machine longitudinal axis of the turbomachine and by means of a movement is locked positively and in particular non-rotatably with the blade shaft in a second assembly direction, an assembly method and a turbomachine.

Reference number

1

Blade shaft

2

Lever connection

4th

casing

6th

Adjusting lever / lever

8th

Adjustment ring

10

Adjustment ring pin

12

Screw element

14th

Connection section

16

Contact area

18th

further connection section / connection section

20th

strip-like lever section

22nd

Recess

24

Long hole

26th

Wrench flat

28

Wrench flat

30th

Concave surface

32

Threading opening

34

free end of the blade shaft / radially outer shaft area

36

Through hole

38

Contact area

40

Contact area

42

Peripheral surface

44

adjacent shaft area radially inside

46

Shoulder surface

48

Shoulder surface

50

Ring groove

52

Washer

54

Bearing bush

56

Ring shoulder

58

Opening in the adjustment ring

H

Vertical axis

X

Machine longitudinal axis

B.

Lever width direction

L.

Longitudinal direction of the lever

Claims (9)

1. Lever connection (2) of a guide vane adjustment means of a turbomachine, for establishing a connection between a guide vane and an actuator, the guide vane having a vane shaft (1) which extends in the radial direction along the vertical axis (H) thereof and which can be brought into connection with an adjusting ring (8) of the actuator by means of a lever (6), the vane shaft (1) having a contact region (16) which has a reduced cross section compared to a radially outershaft region (34);
   characterized in that the lever (6) has a connection portion (14) having an elongate hole (24) and a thread-in opening (32), the elongate hole (24) having key flats (26, 28) for rotationally fixed operative connection with correspondingly designed contact surfaces (38, 40) of the contact region (16), the thread-in opening (32) transitioning on the circumference thereof into the elongate hole (24), and the thread-in opening (32) having an enlarged cross section compared to the elongate hole (24) and being designed such that the lever(6), by means of the connection portion (14) thereof, can be slid radially onto the vane shaft(1) via the thread-in opening (32).
2. Lever connection according to claim 1, wherein the key flats (26, 28) and the contact surfaces (38, 40) are parallel surfaces.
3. Lever connection according to either claim 1 or claim 2, wherein the contact surfaces (38, 40) are formed by lateral cross-sectional tapers of the vane shaft (1), and the contact surfaces (38, 40), in each case via a shoulder surface (46, 48), transition into a shaft region (44) which is radially adjacent to the contact region (16) on the inside, which shoulder surfaces form supports for the connection portion (14).
4. Lever connection according to claim 1, 2 or 3, wherein the lever (6) is clamped on the vane shaft (1) by means of a screw element (12) which interacts with the radially outer shaft region (34).
5. Lever connection according to claim 4, wherein, when the screw element (12) is mounted, the connection portion (14) of the lever (6) is clamped between the shaft-side shoulder surfaces (46, 48) and the screw element (12).
6. Lever connection according to any of the preceding claims, wherein th e lever (6) cooperates with an adjusting ring pin (10) so as to be connected to the adjusting ring (8), which pin is designed such that the connection to the adjusting ring (8) takes place by means of a radial movement of the lever (6).
7. Method for establishing a connection between a guide vane and an actuator, wherein the guide vane has a vane shaft (1) which extends in the radial direction along the vertical axis (H) thereof and which is indirectly or directly brought into connection with an adjusting ring (8) of the actuator by means of a lever (6), wherein the lever (6) is slid radially onto the vane shaft (1) from a first mounting direction, and is then form-fittingly locked to the vane shaft (1) by means of a movement in a second mounting direction which is different to the first mounting direction.
8. Method according to claim 7, comprising the steps of:

   • radially sliding the lever (6) onto the vane shaft (1) via a lever-side thread-in opening (32) and radially connecting the lever(6) to the adjusting ring (8),

   • axially sliding the adjusting ring (8) together with the lever (6) along a lever-side elongate hole (24) until opposing key flats (26, 28) of the elongate hole (24) are in contact with corresponding contact surfaces (38, 40) of the vane shaft (1),

   • clamping the lever to the vane shaft (1) by means of the interaction of a screw element (12) with a radially outer shaft region (34), wherein the lever (6) is radially clamped between the shaft-side shoulder surfaces (46, 48) and the screw element (12).
9. Turbomachine comprising a plurality of lever connections (2) according to any of claims 1 to 6 for establishing a connection between guide vanes of an adjustable vane row and an actuator.

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